It’s not enough for Walmart to have a market capitalization of $200 billion — more than the GDP of 147 countries worldwide. Or for Nokia to sell 420 million new phones in a year — increasingly to developing countries in Africa and Asia. People expect global brands to use their vast resources to make the world a better place. Now more than ever, consumers are making decisions based on companies’ social agendas — and market share hangs in the balance.

While Walmart supports everything from women’s empowerment to disaster relief through its foundation, the public is expecting even more from major tech companies like Google, Facebook and Amazon. Not only do they have some of the most visible wealth, they’re also intrinsically innovative — capable of solving some of the world’s hardest engineering problems and creating sustainable solutions.

As investment in social enterprise becomes more common, major brands and venture capitalists alike are learning how to make a difference without sacrificing their profit-driven missions.

Nokia is a prime example. With 51% of the mobile market share in Africa, it’s one of the continent’s most recognizable brands. Lacking televisions, computers — and, in some cases, electricity — many people throughout Africa access information and communicate solely through their mobile phones. Nokia has not squandered this opportunity — it’s using it to extend affordable, life-changing services and tools to African farmers.

Through its Ovi application store, Nokia offers Ovi Life Tools, an SMS-based app available on extremely cost-effective handsets that provides farmers with timely weather and agricultural information to optimize preparedness and crop yields. Nokia partners with organizations like the Kenya Meteorological Department, agriculture NGOs, and more to serve up tips, techniques and market stats that could help them prevent food shortages and get the best prices for their goods. Life Tools is also being used to deliver lesson plans to teachers, learning games to kids and accounting services for small businesses.

Facilitating connections between people and expanding access to global networks is one major way tech companies are doing their part for social good. Both Twitter and Facebook exploded last year during Arab Spring, becoming primary platforms for coordinating rallies, organizing protests and disseminating news and information quickly among millions of young people. Nine in 10 Egyptians and Tunisians surveyed by the Dubai School of Government said they organized or found out about protests on Facebook alone.

These social networks found themselves playing huge roles in historical democratic movements, and gaining users by the millions. The number of Facebook users in the region jumped by 30%, and tweets from Egypt jumped from 2,300 to 230,000 in the week before Egyptian President Hosni Mubarak’s resignation. It might seem counter-intuitive for platforms essentially created for entertainment to be playing key roles in geopolitical events, but in this case, revolution was also good for business.

Like Twitter and Facebook, Google also provides tools that have helped people around the world communicate, organize, and be more productive. But its made a more concerted effort to not just promote social good, it’s investing in it too. In 2009, it created Google Ventures, a venture capital investment arm that funds for-profit tech startups. And while its investments are financially motivated, many of the companies it backs have strong social missions.

All six of Google Ventures’ energy-related portfolio companies are pursuing clean, efficient and renewable energy solutions. They include Nest, maker of the world’s first learning thermostat that helps users become more energy-efficient, and attracted a lot of buzz for its sleek, Apple-esque design. Its life science portfolio is stacked with companies pursuing innovative cancer therapies and genetic diagnostic systems to make medicine simpler, leaner and more affordable. And even some of its mobile picks have a social bent, like Miso Media, which creates entertaining educational software to make learning fun and easy.

Google may be more overtly philanthropic through Google.org — it gave away $115 million in grants and over $1 billion in in-kind support to nonprofit and educational orgs last year alone — but, in many ways, Google Ventures is more indicative of the future of tech brands and social enterprise. It combines doing good with doing well, a hard balance to strike.

That said, it’s a balance pursued not only by big names in tech, but also by the VCs trying to find and fund the next generation of big names. More and more, venture capital firms in Silicon Valley are seeking out socially-minded startups that have the potential to make money and a positive impact at the same time.

Marquee firms like Khosla and Kleiner Perkins are investing heavily in cleantech startups like Ecomotors, Stion, Sundrop Fuels, and Fisker Automotive. Kleiner even launched what it calls its Green Growth Fund to support later-stage greentech ventures that have gained traction and have the potential to slow climate change.

On the far end of the spectrum, you have firms like social enterprise incubator Hub Ventures and Omidyar Network, which exclusively seek out companies looking to do good in the world. The latter not only gives grants to a slew of nonprofits, it funds for-profit microfinance organizations and consumer tech companies focused on connection building and information sharing like Digg, Meetup and Wikia.

Across the board, Silicon Valley seems to be waking up to the reality that having resources and brainpower obligates them to do more for the rest of the world. With consumer eyes fixed on which brands do what — whether it’s Facebook’s Mark Zuckerberg giving $100 million to Newark Public Schools, or Amazon launching an environmentally-friendly packaging initiative — it’s more important than ever for tech companies to do their part.

That said, if recent examples prove anything, it’s that making money and a difference don’t have to be mutually exclusive.

Finding these ideas that sit at the intersection of impact and profitability is what the Grand Challenges Exploration program is all about. A grant program funded by the Bill and Melinda Gates Foundation, the program is looking for bold, creative ideas to solve the biggest problems in global health. People from all disciplines, age groups and professions are encouraged to apply. In the past, the program has seen groundbreaking submissions come from unexpected sources, from astrophysicists to mechanical engineers to students.

The deadline for submissions to this year’s program is May 15. Successful projects will win support and have the chance to land $1 million in additional funding to bring their ideas to fruition — and maybe even change the world!